const fs = require('fs');

let promise = new Promise((resolve, reject)=>{
    fs.readFile('./11.txt','utf8',(err,result)=>{
        if(err != null){
            reject(err);
        }else{
            resolve(result);
        }
    })
})

promise.then((result)=>{
    console.log('result :>> ', result);
}).catch((err)=>{
    console.log('err :>> ', err);
})